An LCD device includes a plurality of PCBs such as a power board, a master control board, an interface board, a key board, a remote control board, etc. Some PCBs are provided with many circuits and components. The LCD devices are designed to be thinner, and the PCBs are designed to be thinner and smaller. Thus, the components on the PCBs are densely arranged, and the heat dissipating area is insufficient, resulting in the overhigh temperature of some components, and affecting the performance of the PCBs. Especially, the component with high heat productivity such as an IC (integrated circuit), a metal oxide semiconductor transistor (MOS transistor), etc. on the power board and the master control board are easier to be damaged because of overhigh temperature, thereby requiring to improve the heat dissipating performance of PCBs.